If you can even find a 1080P TV, it's going to be a very low-end model. Pretty much everything on the market is 4k, so it's just a matter of how much money you want to save. That being said, the difference between something like a 65" OLED and a 65" Vizio D-series is going to be around $1,000-1,500. That can get you a nice, used audio setup. And, unlike video, a good set of speakers will last you decades, the main replacement being the receiver. If I were in your shoes, I'd spend most of the money on the sound setup, and use the remaining money to buy a TV. Then, whenever you get sick of the TV, you just replace it.